Refrigerated counter-top display case



Jan. 2, 1968 w. DIE KMANN 3,360,953

REFRIGERATED COUNTER-TOFDISPLAY CASE Filed Dec. 29, 1966 Y 2 Sheets-Shet 1 INVENTOR GEORGE WILLIAM DIECKMANN ATTQR NEY Jan. 2, 1968 G. w. DIECKMANN 3,3

' REFRIGERATED CQUNTER-TOP DISPLAY CASE Filed Dec. 29, 1966 2 Sheets-Sheet z 23 m INVENTOR 20 x ggwm ATTORNEY Geoace WILLIAM DIECKMANN United States Patent 3,360,953 REFRIGERATED COUNTER-TOP DISPLAY CASE George William Dieckmann, Riverview Gardens, Mo., as-

siguor to Food Equipment Corporation, St. Louis, Mo., a corporation of Missouri Filed Dec. 29, 1966, Ser. N 605,906 5 Claims. (Cl. 62-249) ABSTRACT OF THE DISCLOSURE A counter-top refrigerated display case utilizing undercounter refrigerating machinery which supplies an evaporator coil within the top rear portion of the trans parent case. The coil is concealed behind up-flow louvers and between an exterior service shelf above and a multiple vane-like drip tray below the coil. Rapid downward circulation of chilled air at rear of the case permits a sliding door to stand open.

The present invention deals with refrigerated countertop display cases, and in particular to those in which the evaporator coil is contained within a transparent countertop display unit and the remainder of the refrigerating apparatus is supported beneath the counter.

The principal purpose of such a case is to display food effectively while preserving it chilled and ready to serve. Heretofore (as in US. Patent No. 2,973,631 to Adkins) the commercial importance of concealing the evaporator coil has been recognized. In that patent, concealment was effected by incorporating the evaporator coil in a cold.

plate or refrigerated bottom surface within the display unit. This location sacrifices the convection flow of chilled air, for if such air cannot move downward it will not tend to circulate. Food portions displayed in a customary manner, for example, on china plates, cannot be satisfactorily cooled by conduction to a refrigerated surface; further without circulating air, the space above the bottom would be of little use.

The principal objects of the present invention include achieving substantial concealment of the evaporator coil from view and at the same time achieving a greatly improved circulation of chilled air by convection, thus to effectively refrigerate the entire volume of the display case. Additional objects include providing an uninterrupted downflow of chilled air in front of the rear doors of the display case, at a rate so rapid as to permit such a door to remain open for substantial periods of time. Further objects will be apparent from the following disclosure.

Generally summarizing (but without limiting) the present invention, an elongated finned evaporator coil is supported lengthwise in the display case transparent enclosure, closely beneath its upper surface and closely forward of rear doors. Concealment from above and from the sides and rear is effected by an exterior opaque service shelf which covers the rear portion of the top surface of the display case; concealment from the front is effected partly by the overhang of the shelf forwardly of the evaporator coil and partly by shallow coil-concealing louvered air inlet which extends downward beneath the shelf forwardly of the coil. If viewed from the front the louvered air inlet will be visible, forming in effect the front element of a shallow compartment in which the coil is concealed. If viewed slightly from below, there will be visible, as an apparent bottom to such compartment, the flat lower surfaces of adjacent drip trough elements beneath the coil.

Rapid circulation of convection air is induced by the chilling effect of the evaporator, together with the provisions made for rapid patterned air-flow. These provisions include the up-fiow air inlet louvers, which cause air passing to the coil to be drawn upward-and-aft to a level above the tubing of the evaporator coil; and vanelike leading edge portions of the drip trough elements, which project forward and upward from the apparent bottom made up of the lower surfaces of these elements. The chilled air, passing aft and downwardly through adjacent fore-and-aft fins on the coil tubing, is guided by the forward undersurfaces of these vane-like portions in a downward-and-aft turning path, to exit through air conducting passages betweent he adjacent drip trough elements and drop rapidly in front of the rear doors of the enclosure.

In the accompanying drawings:

FIG. 1 is a perspective view of a refrigerated countertop display case embodying the present invention, shown from the rear and partly broken away to reveal the concealed evaporator unit.

FIG. 2 is an enlarged fragmentary detail section taken along line 22 of FIG. 1.

The display case illustrated consists of two principal portions, a transparent counter-top enclosure generally designated 10 and an under-counter refrigeration section generally designated 20, the latter mounted on a pair of square tubular frame members 11 which extend downward from the enclosure 10, for support below a countertop designated a, shown in phantom lines.

The enclosure 10 has an insulated rectangular base 12, a transparent front surface 13 made of plastic or plate glass, similar left and right end surfaces 14 and top surface 15, and a pair of transparent sliding rear doors 16 set in upper and lower extruded tracks 17. The refrigeration section 20 is a rectangular compartment which may include a structural shelf 21 extending rearwardly from the lower ends of the square tubular frame member 11. Within its front end is supported a shallow drawer-like drip pan 22, removable by sliding forward as shown in dashed lines. Within the compartment 20, conveniently supported by the shelf 21 or other structure, are a conventional refrigeration motor compressor b, condenser c, and an expansion valve 1 Perforated vertical side plates 23 for the refrigeration section 20 permit ventilated operation.

To place the display case in position on the countertop a, it is placed at the rear of the counter-top a and raised so that the base 12 is slightly above the level of the counter-top a; then it is moved forward until the rectangular posts 11 rest against the rear edge of the countertop a. Thumb screws 24 in angle brackets 25 along the upper edges of the plates 23 at each side of the refrigeration section are then turned to project upward and bear tightly against the under side of the counter-top a.

At the rear side of the unit, as shown in FIG. 1, a refrigeration control switch 26 is mounted on an upper fixed panel 27 between the tubular frame members 11. A removable lower panel 28, extending downwardly from the upper panel 27 to the removable drip tray 22, provides access for servicing. All the refrigeration elements are conventional.

Ascending from the valve v is a refrigerant supply tube 31 which passes upward between the frame members 11 aft of the counter-top a, and then extends horizontally to the right through the insulated base 12, to near its right end. From this point it rises vertically to join the evaporator coil generally designated 32, not only supplying it with refrigerant but also supporting its end shown at the right side of FIG. 1. A refrigerant return tube 33 similarly supports its other end, at the left side of FIG.

1, which descends vertically, then passes horizontally through the base to a point between the frame members 11, and then downward to return the warm refrigerant to the compressor b.

The coil 32 is of the type having several laterally-extending runs of tubing 34 connected by end loops 35 so as to lie in a horizontal plane. Vertical forward and aft convection fins 36, indented to receive the tubes 34 and brazed thereon, define the depth of the evaporator coil from front to rear and also define its vertical height, which as shown in FIG. 2 is substantially less than its depth from front to rear.

The refrigerant supply tube 31 and the refrigerant return tube 33 thus serve as a simple means to support the evaporator coil 32 in a laterally-extending position adjacent to the upper enclosure surface and closely forward of its sliding rear doors 16. Since the length of the coil 32 is nearly as great as the length of the enclosure 10, the coil 32 has been found to have adequate capacity even though the vertical height and the front to rear dimensions defined by the fins 36 are quite small.

The manner in which the coil 32 is substantially concealed and an improved return of circulation of air is obtained, will now be described. As shown in FIG. 1, the evaporator coil is concealed from the top, sides and rear by an exterior opaque service shelf generally designated 40, preferably formed of stainless steel, as is the exterior of the base 12. Its top surface portion 41 covers the entire rear portion of the top surface 15 of the enclosure and extends forward to overhang forwardly of the evaporator coil 32. A rear portion 42 extends downwardly below the level of certain drip trough elements to be described, and its left and right end portions 43 extend downwardly the same distance, so that, if viewed from above and from the rear and sides, the evaporator coil 32 is completely concealed. The service shelf 40 is usefully located, and the rear and end portions 42, 43 are modest in extent and of the same depth as the base 12.

Beneath the evaporator coil 32 are a plurality of spacedapart laterally-extending drip trough elements generally designated 45. In FIG. 2 these are shown as viewed from their left ends, toward which they slant downward. Each drip trough element 45 has a substantially flat lower surface 46 bounded at the rear by an upward extending aft flange 47 which defines its depth for conducting water to the left end, at which drain means is provided as hereafter described. Each drip trough element 45 has a vanelike leading edge air-deflector portion 48 which serves as a front trough flange to provide adequate capacity for conducting water which may drip from the evaporator coil 32. Each air-deflector portion 48 commences at a level substantially higher than the aft flange 47. When assembled as shown in FIG. 2, the leading edge air-deflector portion 48 of every drip trough element 45 aft of the front one (shown to the left in FIG. 2) is spacedly above the aft flange 46 of the element 45 forward of it. Thus lateral air-conducting passages are provided between the adjacent drip trough elements 45. While the upper, rear-slanting surfaces of the air-deflector portions 48 catch dripping moisture, their under, forward-facing surfaces serve as vanes to turn the convection air.

The drip trough elements 45 are spot-welded (or otherwise secured) onto bent metal supporting straps 50 at their left and right ends. The straps 50 are secured as by riveting through the transparent enclosure top 15 to the metal service shelf 40. Near the rear edge, immediately forward of the upper and lower extruded tracks 17, the straps 50 first descend vertically to the level at which the lower surfaces 46 of the drip trough elements 45 are to be supported, thence forwardly beneath them, thence slantingly upward along the vane-like leading edge airdeflector portion 48 of the front drip element 45 to a point spacedly forward of the fins 36, and thence vertically upward to the top surface 15, for riveting through it to the service shelf 40 adjacent to its forward margin.

Beneath the strap 50 at the left end of the drip trough elements 45 is secured an upper side support flange 51 4 of a fore-and-aft drain trough 52. Through its bottom a drain tube 53 leads downward to the insulated rectangular base 12, through it alongside the refrigerant return tube 33, and downward inward of the left vertical post 11 to drain into the shallow drawer-like dri-p pan 22.

Where the support straps 50 rise vertically in front of the evaporator coil 32, as shown in FIG. 1, coil-concealing air inlet flow means are provided, specifically a plurality of sheet-metal louvers 55. As viewed from the front, each is substantially horizontal; but as viewed edgewise in FIG. 2, each consist of an aft and upward sloping portion 56 and a short vertical portion 57 spot Welded at its left and right ends to the straps 50. When viewed directly from the front and above, a clean-out, uncluttered, non-mechanical appearance is presented. If viewed partly from above, the overhang of the service shelf 40 forwardly of the evaporator coil 32 serves to conceal it almost entirely.

Considering FIG. 2, if viewed from the front and somewhat from below, the succession of flat lower surfaces 46 of the drip trough elements 45 will seem to be uninterrupted, thus presenting the appearance of a compartment smoothly enclosed from below.

The air inlet means provided by the louvers 55 above the air deflector portion 48 of the foremost drip trough element 45, cooperate with the vane-like air deflector portions 48 and the air-conducting passages forward of them to provide the unique rapid flow of convection air achieved in the present invention. As is known, chilling air serves to shrink its volume and thus to increase its weight. The present invention applies this principle to achieving a smooth turning of the air flow which permits it to build up a rapid rate of circulation. The inlet louvers 55 direct inflowing air upward and aft, to flow between the convection fins 36 of the evaporator coil 32, initially at a level above that of the tubes 34 of the evaporator coil 32. Flow is shown schematically by arrows in FIG. 2. As the air so introduced to the coil 32 becomes chilled, its aft flow is turned increasingly downward. The forward undersurfaces of the vane-like leading edge air deflector portions 48 serve to direct this downward-and-aft flow through the air passages between the adjacent trough elements 45. So rapid is the downflow of chilled air immediately forward of the rear doors 16, that it induces or augments the flow of air immediately forward of the chilled air, as shown in the dashed arrows in FIG. 2. The downward-slanting forward surface 48 of the foremost trough element 45 aids in turning this air downward.

One result of the rapid downflow of chilled air is to complete the circulation pattern by drawing air rapidly upward and aft through the inlet louvers 55, Another result is to provide an air door effect; the flow circulates downward so rapidly that, with the refrigeration unit operating normally, opening one of the sliding doors 16 does not interrupt the circulation pattern of refrigerated air.

Modifications may be made in the apparatus illustrated without departing from the teachings of the present invention. Accordingly this invention should not be construed narrowly but rather as co-extensive with the claims.

I claim:

1. A refrigerated counter-top display case including a transparent counter-top enclosure having rear door means and having downward extending rear support means,

refrigeration apparatus supported by said support means and thereby positioned spacedly below the transparent enclosure, and

an elongated evaporator coil within the enclosure and connected to said apparatus, the coil having forward-and-aft convection fins defining a vertical height substantially less than its depth from front to rear,

wherein the improvement comprises means to support the evaporator coil in laterally-extending position adjacent to the upper surface of the enclosure and closely forward of its rear door means, laterally-extending drip trough elements therebeneath adjacent to each other and slanting downward toward one end and having lateral air-conducting passages between the adjacent elements, drain means at the lower end of the drip trough elements, an exterior opaque service shelf covering the rear portion of the top surface of the enclosure and overhanging forwardly of the evaporator coil, and coil-concealing air-flow inlet means forwardly of the coil beneath the shelf, whereby as viewed from the front and above, the transparent enclosure presents an open, uncluttered appearance. 2. A refrigerated counter-top display case as defined in claim 1,

the opaque service shelf further having downward extensions at each lateral edge and covering side surface portions of the transparent enclosure to below the level of the drip trough elements, and similarly at the rear, whereby to conceal the evaporator coil from view from the sides and rear. 3. A refrigerated counter-top display case as defined in claim 1,

each drip trough element having a substantially fiat lower surface and an aft flange extending upward, thereby to define its depth for conducting water to the drain means, whereby to provide above said flat surface for adequate water-flow capacity to the drain means and whereby the succession of said substantially flat lower surfaces of the successive drip trough elements, taken together with the air inlet means and viewed somewhat from below, presents the appearance of a smoothly enclosed compartment for the coil. 4. A refrigerated counter-top display case as defined in claim 1,

each drip trough element having an aft flange extending upward, thereby to define its depth for conducting water to the drain means,

each drip trough element aft of the front element having a vane-like leading edge air deflector portion commencing spacedly above the aft flange of the trough element forward of it, thereby to conduct air aft and downward along the forwardly-presented undersurface of said vane-like portion,

the front drip trough element having a similar vanelike portion commencing the air inlet means and extending slantingly downward and aft therefrom,

whereby to turn downward the aft-flowing convection air immediately beneath that which flows through the air inlet means to the evaporator coil and thus to provide augmentation of circulation adjacent to the chilled air emerging through the drip trough means.

5. A refrigerated counter-top display case as defined in claim 1,

wherein the tubing of the evaporator coil extends generally laterally, and

the air inlet means includes louvers which slope aft and up,

whereby to direct air upward and aft to a level above the evaporator coil tubing, from which it flows first aft, and then turns increasingly downward between the fins to exit through the air conducting passages between the adjacent drip trough elements,

thereby providing a curving pattern of air-flow in which chilling the air at the evaporator coil causes rapid circulation downward in front of the door means.

References Cited UNITED STATES PATENTS 1,614,319 1/1927 Schmidt 62-246 WILLIAM J. WY E, Primary Examiner, 

